It is well known to including advertising insert cards (xe2x80x9cblow-insxe2x80x9d) with no adhesive in magazines for promotional purposes. These insert cards simply sit between pages loosely and may fall out when the magazine is read. Typically, such insert cards are in the form of a postcard for the reader to complete and return.
Repositionable sheets, such as the POST-IT(copyright) brand notes sold by Minnesota Mining and Manufacturing Company of St. Paul, Minn., are quite common and in every day use. Such sheets in familiar form are available in stacks or pads of sheets, one adhered to another. Such repositionable sheets have a first side which is partially coated with a repositionable pressure sensitive adhesive (RPSA) and a second side which is either plain (no printing) for writing a note, or which may have a preprinted message or design thereon. Such repositionable sheets are useful for calling attention to a particular section of a document, for marking pages in documents or books, or for leaving removable and repositionable notes that can be adhered to just about any clean surface.
The utility of placing a repositionable sheet on an advertising signature, flyer, newspaper, magazine, etc. has also been noted. An advertising signature is an insert that is placed in a magazine and comprises a plurality of pages, typically rectangular pieces of paper having advertising printed thereon and being folded over to form a registration edge. When placed in a magazine, the advertising signature is bound to the other magazine pages along the registration edge. Advertising signatures have been provided with repositionable labels that contain information such as the name and telephone number of the advertiser or a coupon for a price discount. The labels are repositionable so that they can be removed from the advertising signature and adhered at another location (for example, a desk or refrigerator) to remind the reader to call the advertiser or to use the coupon at a later date.
Many of such labels that have been placed on advertising signatures have a repositionable pressure sensitive adhesive (RPSA) coated over the entire back side of the label. Labels that have RPSA coated over their entire back side are typically carried on a liner before being adhered to an advertising signature. The labels on the liner are supplied to an apparatus which separates the label from the liner and adheres the label to an advertising signature. The label is typically separated from the liner by a peeler bar, and the label is subsequently adhered to a substrate (that could be an advertising signature), typically by a blast of air. The liner, which previously supported the label, often is rewound on a take-up reel and subsequently discarded as waste. These methods and apparatus have drawbacks in that they generate waste in the form of a useless liner, require additional equipment on the apparatus to remove the label and store the liner (for example, a peeler bar and take-up reel), and use excess quantities of adhesive by having the entire back side of the label coated with RPSA.
In another approach to promote an advertisement in an advertising signature, a backer card is employed to secure a repositionable, information-containing sheet to an advertising signature. See U.S. Pat. No. 4,842,303, incorporated herein by reference. The backer card has a registration edge which is aligned with the registration edge of the advertising signature. The repositionable sheet of paper has a narrow band of RPSA coated on one surface adjacent to an edge of the repositionable sheet. The repositionable sheet is adhered along the registration edge of the backer card by the narrow band of RPSA. The combination backer card and repositionable sheet is secured to an advertising signature by gluing the backer card to the advertising signature using, for example, a tipping machine.
Although the approach disclosed in U.S. Pat. No. 4,842,303 employs an information-containing sheet which only uses a narrow band of RPSA, it too has a number of drawbacks. One drawback is the need to employ a backer card to secure the repositionable sheet to an advertising signature. Another drawback is the need for a number of additional process steps to assemble the combination backer card/repositionable sheet before it is attached to an advertising signature. The additional process steps that have been used include: laminating the adhesive bearing sheet and backer card together in registry; cutting the laminated webs to a master sheet size (typically, 8.5 by 12 inches); stacking the cut master sheets; jogging the master sheets; cutting them into conventional sizes (for example, 4 inches by 6 inches); stacking the cut laminated sheets; and then shipping them to an inserter for attachment to an advertising signature.
It is believed that the only publicly known method for directly applying linerless repositionable preprinted sheets having a band of adhesive thereon directly onto articles such as magazines or advertising signatures is by manual means. A previous method and apparatus for an automated application of such sheets is disclosed in co-pending U.S. patent application Ser. No. 08/963,147, which is a divisional of U.S. patent application Ser. No. 08/095,722, now abandoned, commonly owned by the assignee of the instant application, Minnesota Mining and Manufacturing Company, St. Paul, Minn., and incorporated herein by reference. In that disclosure, a supply roll of paper for forming such sheets is incrementally dispensed, cut by a reciprocating knife, and then transported to a flat vacuum plate, which first held the cut sheet by forming a vacuum and then blew the RPSA side of the cut sheet onto an advertising signature. In this arrangement, a series of indicia (i.e., xe2x80x9ceyemarksxe2x80x9d) printed on the RPSA side of the sheet material were detected to control the movement of the sheet material through the apparatus and its alignment relative to its respective advertising signature. The locational placement of the cut sheet relative to the advertising signature is referred to as its registration. At the highest speeds possible with this equipment (e.g., 3,000 articles processed per hour), this prior art apparatus did not provide as precise a placement or registration of the cut sheet on sequential advertising signatures as desired.
The present invention relates to a new method and apparatus for applying adhesive sheets directly to an advertising signature or other article. Initially, the sheets are provided in roll form for processing and application. In one embodiment, a roll of sheet material is elongated longitudinally, has first and second opposed sheet surfaces and first and second opposed side edges. A pressure sensitive adhesive extends in a predetermined pattern on only a first adhesive portion of the first surface of the sheet material, adjacent the first side edge thereof. The sheet material, adjacent its first side edge and including the first adhesive portion, is formed from a material that is sufficiently transparent when adhered to a substrate that underlying images on the substrate are substantially visible through the sheeting material. The sheet material also has a plurality of longitudinally spaced and detectable images disposed in predetermined locations on the first adhesive portion thereof. In an alternative embodiment, the sheet material in roll form is entirely opaque and has a plurality of equally-spaced, longitudinally disposed images printed on both sides thereof, with the images on the side bearing the pressure sensitive adhesive serving as registration means for use in processing the sheet material.
A method of sequentially adhering linerless sheets to a corresponding sequence of articles comprises supplying (a) an elongated linerless sheeting in wound roll form, with the sheeting having a first major side and an opposed second major side. A pressure sensitive adhesive coating partially covers the first side of the sheeting, while the second side of the sheeting is free of adhesive. (b) A leading portion of the elongated linerless sheeting is advanced along a process path until it reaches a cut station. (c) The leading portion of the linerless sheeting is laterally cut to define a first cut sheet having a first lead edge and a second trailing edge. (d) A vacuum platen having an arcuate circumferential surface is aligned in engagement with at least a portion of the second side of the first cut sheet adjacent the first lead edge thereof. (e) A negative pressure is drawn on a portion of the arcuate circumferential surface of the vacuum platen to affix the first cut sheet in the cut station thereto. (f) A first article having a face is advanced into an applicator station adjacent the vacuum platen. (g) The vacuum platen is moved to carry the first cut sheet from the cut station to the applicator station, whereby the first cut sheet is aligned for placement on the face of the first article. (h) The negative pressure on the arcuate circumferential surface is relieved to release the first cut sheet from the vacuum platen. (i) The vacuum platen is moved across the face of the article so that the pressure sensitive adhesive on the first side of the first cut sheet is pressed against the face of the article to bond the first cut sheet to the face of the article. Steps (b) and (c) are repeated to define a second cut sheet from the elongated linerless sheeting. Steps (d) and (e) are repeated with the vacuum platen relative to the second cut sheet. The second article having a face is advanced into the applicator station adjacent the vacuum platen. Steps (g), (h) and (i) are repeated with the second cut sheet to align, release from the vacuum platen and then press the second cut sheet against the face of the second article by the arcuate circumferential surface of the vacuum platen.
In one embodiment, the elongated linerless sheeting processed by the above-described method is light transmissive. Preferably, the light-transmissive sheeting has, on either side, a series of longitudinally disposed, equally spaced visual indicators, and the method further includes the step of detecting each visual indicator on the sheeting as it is advanced along the process path to generate a signal used for process control purposes.